Consequently, and from the data available, the influence of p53 status on the radiosensitising effect of Chk1 inhibition could be tumour type and/or inhibitor specific, although more investigative studies are required to fully determine whether p53 mutational status is indeed a pre-requisite for a preferential response to Chk1 inhibitors in combination with radiation. Here, CHEK1 is linked to neoplasm.